遥感和GIS支持下的湘西北喀斯特山区县域农业生态环境脆弱度评价

将GIS和遥感技术引入传统的脆弱度定量评价方法,采用专家咨询法和层次分析法建立指标体系,应用GIS建立评价模型,对典型的湘西北喀斯特山区农业生态环境脆弱度进行了评价。结果显示,研究区存在澧水河谷和以罗水乡为中心西北部两个农业生态环境脆弱度高值区,农业生态环境脆弱度分布与由人类活动所致的胁迫脆弱度分布匹配。根据评价结果,为了避免农业生态环境退化,应采取加强东南和西北山区坡耕地退耕还林、增加水田比重和减少西北农业区农药、化肥和地膜的使用量等措施。

Evaluation of Vulnerability of Agriculture Eco-Environment in Karst Mountain Areas in Northwestern Hunan Based on GIS and RS

The agriculture eco-environment of Karst mountain areas in Northwestern Hunan is typically vulnerable.Traditional methods of vulnerability evaluation can not get accurate result because the methods are based on administrative region and statistical data are used.To improve the accuracy the technologies of GIS and RS are used in this study.The expert referring method and Analytic Hierarchy Process method are used to build indexes system,RS technology is mainly used to get regional data of the study area,and GIS technology is used to build evaluation model and evaluate the agriculture vulnerability distribution.The results of evaluation showed that 1)the difference of the distributions of structure vulnerability and menacing vulnerability is obvious,the range of structure vulnerability value is small,and the distributions of high value area mainly locate in mountain areas,2)the distribution of menacing vulnerability looks like two cross bands,the range of menacing vulnerability value is large,and the Luoshui Town get the maximum value,3)there are two high value regions of agriculture eco-environment vulnerability,the first is the Lishui river valley and the other is Luoshui Town,and the distributions of agriculture vulnerability and menacing vulnerability can be matched.To decrease the risk of ecology degradation,some policies should be taken.The first is returning farmland to forest in north-west area and south-east area,the second is decrease the proportion of dry land area,the last is using less pesticides,fertilizer and mulch.